[Invokers] Reland: Add HandleInvokeInternal on HTMLDialogElement

(This relands
https://chromium-review.googlesource.com/c/chromium/src/+/4987322 after fixing timeout issues in
https://chromium-review.googlesource.com/c/chromium/src/+/5372478)

This adds support for the experimental `invoketarget` behavior for
HTMLDialogElement.

See explainer section here:
https://open-ui.org/components/invokers.explainer/#defaults.

This introduces new behavior for HTMLDialogElements such that:

 - If an `invoketarget` points to a `<dialog>` (and the parent logic
   fell through):
    - If the `invokeaction` is `` (empty - the auto state) try to toggle the dialog as modal.
    - If the `invokeaction` is `close`, try to close the dialog
    - If the `invokeaction` is `showModal`, try to show the dialog as
      modal.

Bug: 1494810
Change-Id: Ic178239b8597df8746d9b4cde8f2efe53290e3ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5389304


Commit-Queue: Keith Cirkel <chromium@keithcirkel.co.uk>
Reviewed-by: Joey Arhar <jarhar@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1280317}